Undoubtedly, most of the classic games are on Nintendo consoles. However, I’m sure most of us don’t have those consoles lying around. Still want to play those games? No problem, this guide shows you how to play classic Nintendo games for free on Windows, Mac, or Linux.
You don’t even need to download anything extra because these Nintendo emulators are web-based and will work with any modern web browser — Firefox, Chrome, Opera, Internet Explorer, Safari, etc. — as long as you have Flash or Java installed. Simply find the game you want on each of the respective websites listed below and play. Read on to learn more.
The NesEmu website  is one which includes 8-bit NES games. Consequently, you can find some classics such as Mario Bros, Duck Tales, Legend of Zelda etc. Note that you’ll need to have one of the sites supported browsers such as Firefox, Chrome and Safari to run the games as in the shot below.
The NESBox  website has both 16-bit SNES emulators and NES alternatives built on Adobe Flash. It has 3,671 games among which are Super Mario World, Mario Kart, Mario All-Stars and a Link to the Past. Click Menu > Browse to search through the game library, and pick a game to load.
The site’s emulators have various options. They have a two player mode for some of the multiplayer games. Press F11 to enable the full-screen mode, and you can also configure the game controls by selecting the spanner icon at the bottom left of the emulator. You can also save games, but will have to register and sign in first. This page  provides further details on how you can configure the emulators.
Those searching for Game Boy games, as well as NES and Super NES titles, should check out the Emulation Collective website . This is a website with Java Runtime emulators, and so you should add a Java plug-in to your browser. Click on VirtualGBX to go to the Game Boy site, which also includes Game Boy Color game titles. Then you can check out some of the great retro Game Boy games such as Kirby’s Dream Land, Wario Land, Super Mario Brothers Deluxe etc.
Those are a few of retro game websites where you’ll find a library of classic NES, SNES and Game Boy games. Their emulators are just as effective as the emulator software packages. Enjoy!